Báo cáo toán học: "On Planar Mixed Hypergraphs" pps
Báo cáo toán học: "On Planar Mixed Hypergraphs" pps
... A planar mixed hypergraph may not have
a strong embedding.
We prove an easy lemma on the number of faces of size two in an embedding of a
planar mixed hypergraph:
Lemma 1 Let H be any planar mixed ... of planar mixed hypergraphs
— similar properties of planar mixed hypergraphs were already used in [10, 15].
We address properties of feasible sets and existence of strict col...
Báo cáo toán học: "Colouring planar mixed hypergraphs" potx
... graph as a planar embedding of a
maximal hypergraph such that the faces of the graph correspond to the edges of the
hypergraph.
3 Colouring planar mixed hypergraphs
Let H =(V,C, D) be a mixed hypergraph. ... colouring properties of general planar mixed hypergraphs was first
raised in [13] (problem 8, p.43). It is evident that every planar D-hypergraph is colourable,
just as every...
Báo cáo toán học: "On Feasible Sets of Mixed Hypergraphs" doc
... and of mixed hypergraphs with maximum degree two [11, 12] are
gap-free. Feasible sets of mixed hypergraphs with maximum degree three need not to
be gap-free. The feasible sets of planar mixed ... Kratochv´ıl, H J. Voss: Mixed Hypegraphs with Bounded Degree: Edge-
Coloring of Mixed Multigraphs, Theoretical Comp. Science 295 (2003), 263–278.
[13] D. Kr´al’, J. Kratochv´ıl, H J. Voss...
Báo cáo toán học: "On Mixed Codes with Covering Radius 1 and Minimum Distance 2" pot
... Fak. Ser. Mat., 9 (1979), 185-190.
the electronic journal of combinatorics 14 (2007), #R51 15
On Mixed Codes with Covering Radius 1 and
Minimum Distance 2
Wolfgang Haas
Albert-Ludwigs-Universit¨at
Mathematisches ... and
K
q
(n + 1, 1, 2) ≤ q · K
q
(n, 1, 2), see [4, 3, 8, 6].
A natural generalization is to consider mixed codes with covering radius 1 and mini-
mum distance 2. In the whole...
Báo cáo toán học: "On the Number of Planar Orientations with Prescribed Degrees" pptx
... 05A16, 05C20, 05C30
1 Introduction
A planar map is a planar graph together with a crossing-free drawing in the plane. Many
different structures on connected planar maps have attracted the attention ... we
study bipolar orientations on the square grid, stacked triangulations, outerplanar maps
and planar maps. The upper bound for planar maps relies on a new encoding of bipolar
orientat...
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